Skin cancer is a malignant growth on the skin that can originate from various sources. Three common skin cancers include basal cell cancer, squamous cell cancer, and melanoma. Skin cancer often develops in the epidermis, and is thus often readily detected in early stages. Skin cancer represents the most commonly diagnosed cancer, surpassing lung, breasts, colorectal, and prostate cancer. It has been estimated that approximately 85% of cases of skin cancer are caused by long periods of exposure to ultraviolet (UV) radiation from the sun. Additionally, individuals with lighter skin are more likely to develop skin cancer from such UV exposure.
Sunscreen (or sun-block) is a composition that is applied to a subject's skin in order to absorb or reflects a portion of the sun's UV radiation impinging on the skin that is exposed to sunlight. When used properly and consistently, sunscreen can thus reduce the chances for an individual to develop skin cancer. In addition, sunscreen use can help protect against sunburn. As such, many medical organizations, such as the American Cancer Society, strongly recommend the use of sunscreen as a protection against some forms of skin cancer.